Passive Seismic Characterization of Bedrock and Unconsolidated Glaciofluvial Material

We will be using the Horizontal Vertical Spectral Ratio (HVSR) method for investigation of bedrock depth at various locations in Illinois. Specifically, we are trying to find bedrock depth in a glacial-fluvial bedrock valley in East central Illinois. This serves as a sole-source aquifer for many of the cities in Central Illinois. Helicopter based Transient Electromagnetic (HTEM) data was acquired throughout the project area. HVSR and other ground-based geophysical methods are used for ground-truthing and filling in gaps. HVSR data will be acquired in profiles throughout the project area to better understand the specific contours of the valley and where electromagnetic data may not be able to resolve changes in lithology accurately.